well it is true the audio quality isn't the best, but really the voice talent makes up for it. A lot of times, voices in a flash like this is just grainy, poppy, or acted out badly. Not the case in the slightest. You worked within your limitations and still got great results. Also the animation was good too. Good, pretty original art style with good ways of expressing emotion. I've seen a lot of people just screw this up. I mean, the animation isn't perfect, but its small technical fixes. The art is also pretty good, just some refinements to your art and style, and you are set. I really want to see more. I have high hopes of what's up next.

- also, is that you singing? its great

oh and to answer your audio question, yes it is fixeable.
when you export, look where it says audio stream (assuming your audio is set to stream, PM me if you don't know what I'm talking about) press set then raise the bit rate(not all the way, to like 64 or something, at least until you get to what you want) and quality from there and press okay.